This guide provides an overview of the Digital Distributed Computing
Environment (DCE) for OpenVMS VAX and OpenVMS Alpha and describes
value-added features provided with Digital DCE.
Revision/Update Information:
This guide supersedes the Digital DCE for OpenVMS VAX and OpenVMS
Alpha Product Guide Version 1.3.
Software Version:
Digital DCE Version 1.5
Compaq Computer Corporation Houston, Texas
January 1999
Compaq Computer Corporation makes no representations that the use of
its products in the manner described in this publication will not
infringe on existing or future patent rights, nor do the descriptions
contained in this publication imply the granting of licenses to make,
use, or sell equipment or software in accordance with the description.
Possession, use, or copying of the software described in this
publication is authorized only pursuant to a valid written license from
Compaq or an authorized sublicensor.
Compaq conducts its business in a manner that conserves the environment
and protects the safety and health of its employees, customers, and the
community.
The following are trademarks of Compaq Computer Corporation: Alpha,
Compaq, DECnet, DECthreads, DIGITAL, OpenVMS, VAX, VMS, VMScluster, and
the Compaq logo.
The following are third-party trademarks:
BSD is a trademark of the University of California, Berkeley.
Kerberos is a trademark of the Massachusetts Institute of Technology.
Microsoft, MS, and MS--DOS are registered trademarks and Windows and
Windows NT are trademarks of Microsoft Corporation.
MultiNet is a registered trademark of the Open Software Foundation, Inc.
NetView is a registered trademark of International Business Machines
Corporation.
POSIX is a registered trademark of The Institute of Electrical and
Electronics Engineers, Inc.
UNIX is a registered trademark in the United States and other countries
licenses exclusively through X/Open Co. Ltd.
All other trademarks and registered trademarks are the property of
their respective holders.
ZK6532
The OpenVMS documentation set is available on CD-ROM.
This document was prepared using VAX DOCUMENT, Version V3.2n.
The Digital DCE for OpenVMS VAX and OpenVMS Alpha Product
Guide provides users of the Digital Distributed Computing
Environment (DCE) with the following information:
An overview of DCE and the contents of the Digital DCE product.
The differences between using DCE of OSF/1 and on OpenVMS systems.
The value-added features provided with Digital DCE.
Note
Information on Microsoft's NT Lan Manager is provided as a preview of
functionality that will be available in a future version of Digital DCE
for OpenVMS (Alpha only). This advanced documentation will help you in
future planning.
Intended Audience
This guide is intended for:
Experienced programmers who want to write client/server
applications.
Experienced programmers who want to port existing applications to
DCE.
System managers who manage the distributed computing environment.
Users who want to run distributed applications.
Document Structure
This guide is organized as follows:
Chapter 1 provides an overview of the Digital DCE product and
describes its contents, restrictions, and additional features.
Chapter 2 describes the DCE system configuration utility.
Chapter 3 describes interoperability and compatibility issues.
Chapter 4 discusses using the kit with DECnet networks.
Chapter 5 discusses authenticating RPC using Microsoft's NT Lan
Manager.
Chapter 6 provides information about the names of DCE files and
directories.
Chapter 7 provides information about developing applications on
OpenVMS VAX and OpenVMS Alpha systems.
Chapter 8 provides information about Integrated Login.
Use the following World Wide Web address to order additional
documentation:
http://www.openvms.digital.com:81/
If you need help deciding which documentation best meets your needs,
call 800-DIGITAL (800-344-4825).
Conventions
VMScluster systems are now referred to as OpenVMS Cluster systems.
Unless otherwise specified, references in this document to OpenVMS
Clusters or clusters are synonymous with VMSclusters.
The following conventions are also used in this guide:
Ctrl/
x
A sequence such as Ctrl/
x indicates that you must hold down the key labeled Ctrl while
you press another key or a pointing device button.
italic text
Italic text indicates important information, complete titles of
manuals, or variables. Variables include information that varies in
system output (Internal error
number), in command lines (/PRODUCER=
name), and in command parameters in text (where
device-name contains up to five alphanumeric characters).
UPPERCASE TEXT
Uppercase text indicates a command, the name of a routine, the name of
a file, or the abbreviation for a system privilege.
Monospace type
Monospace type indicates code examples and interactive screen displays.
In the C programming language, monospace type in text identifies
the following elements: keywords, the names of independently compiled
external functions and files, syntax summaries, and references to
variables or identifiers introduced in an example.
Case-sensitivity
OpenVMS operating system commands do not differentiate between
uppercase and lowercase. However, many DCE commands do make this
distinction. In particular, the system configuration utility interprets
names in a case-sensitive manner.
Distributed computing services, as implemented in the Digital
Distributed Computing Environment (DCE), provide an important enabling
software technology for the development of distributed applications.
DCE makes the underlying network architecture transparent to
application developers. It consists of a software layer between the
operating system/network interface and the distributed application
program. It provides a variety of common services needed for
development of distributed applications, such as name and time
services, and a standard remote procedure call interface.
Digital DCE for OpenVMS VAX and OpenVMS Alpha provides a means for
application developers to design, develop, and deploy distributed
applications. This release supports both the OpenVMS VAX and OpenVMS
Alpha operating systems.
Note that the right to use the Runtime Services Kit is included as part
of the OpenVMS license. The other kits each require a separate license.
You must install a kit on each system that will use DCE services.
The following sections list the contents of each of these kits.
The CDS Server kit provides the naming services necessary for DCE
clients to locate DCE server applications. The CDS Server kit includes
the following:
CDS server (cdsd)
Global Directory Agent (GDA) The Global Directory Agent (GDA)
lets you link multiple CDS namespaces using the Internet Domain Name
System (DNS).
The Security Server kit provides the security services necessary for
authenticated RPC calls between DCE client and server applications to
function. The kit includes the following:
Security server (secd)
Tool used to create the security database (sec_create_db)
Digital DCE provides online help for both the management of DCE
services and the development of distributed applications. This DCL help
is organized to maintain the reference page categories established in
the OSF DCE documentation and online reference pages. These categories
are user commands (1), application development support (3), driver and
networking support (7), and administrative support (8).
To access the DCE reference information, use the HELP command. You can
get extensive help on the following DCE top-level topics:
Digital DCE Version 1.5 for OpenVMS VAX and OpenVMS Alpha does not
provide all the functions of the full OSF DCE that will be available at
a later date. The following components are not included in this DCE
product; however, the full OSF documentation is included.
The threads interface is an important part of the architecture for DCE,
and the DCE services rely on it. DECthreads is provided as part of the
OpenVMS VAX and OpenVMS Alpha operating systems. (Note that if you have
OpenVMS VAX Version 5.5-2, you may be asked to install a special kit.)
Refer to the Guide to DECthreads in the OpenVMS operating
system's documentation set for information about threads.
To use RPC only, you begin a configuration as follows:
$ @SYS$MANAGER:DCE$SETUP.COM CONFIGURE or
$ @SYS$MANAGER:DCE$RPC_STARTUP
The DCE Configuration Menu is displayed. From this menu, choose the
RPC_Only option. This option lets you use DCE RPC without a DCE cell.
This option requires applications to use string bindings instead of the
name service to find servers.
To communicate with an RPC server, an RPC client needs the server
binding information. The server binding information includes the
protocol sequences that the RPC server supports and the location (node
name or node address) of the RPC server. When the RPC server is
started, it registers its endpoints with the RPC daemon. It also
exports the binding information to the name server if the name server
exists. The RPC client then gets the binding information from the name
server. When the name server is not available, the binding information
must be provided to the RPC client through other mechanisms.
Users can incorporate in their RPC server code a mechanism for
broadcasting the binding information on the network. However, this may
not be a desired short-term solution. An easy workaround is for the
users to pass the string binding to the RPC client and have the RPC
client call the RPC routine to convert the string binding. In this
case, the users who are running the RPC client need to know two things:
Protocol sequences that the RPC server supports. For example:
ncacn_ip_tcp, ncadg_ip_udp, and ncacn_dnet_nsp. Note that the RPC
client may encounter a communication error if it picks a transport
which is not supported by the server.
Location of the RPC server (the node on which the RPC server runs).
For example: DECnet node name, DECnet address, Internet address, and so
on. You can get this information by executing the following
commands on the server system after the RPC server is started.
$ RUN SYS$SYSTEM:DCE$RPCCP
RPCCP> SHOW MAPPING
See the remote_file example program for an example of using RPC without
CDS and DCE Security servers.
DCE on OpenVMS supports the user deselection of network interfaces on
each system in a DCE cell. Use the logical RPC_UNSUPPORTED_NETIFS which
points to a list of network interfaces delimited by a colon (:) that
you do not want to use.
The routine init_once which is called by RPC at initialization, parses
the list of network interfaces defined with the logical
RPC_UNSUPPORTED_NETIFS, and builds a global list of network interfaces
for deselection by RPC. Routines rpc_ip_desc_inq_addr() and
get_broadcast_addr() call the common routine enumerate_interfaces() to
obtain a list of valid IP addresses for use by RPC. The global list of
network interfaces created in init_once() is parsed to ignore the
deselected interfaces.
DCE V1.5 allows a server to impersonate a client. This means that the
server may run with the security credentials of the client. The
capabilities of the client belong to the server. Table 1-1 lists the
APIs that have been added to support this functionality.
The CDS Enhanced Browser contains additional functions beyond those
contained in the OSF DCE Browser. See the Enhanced Browser chapter for
more information.
The Digital CDS subtree commands allow you to restructure your
namespace. See the chapter titled Using the CDS Subtree Commands to
Restructure CDS Directories for tutorial information on how to use
these commands. See the Digital DCE for OpenVMS VAX and OpenVMS
Alpha Reference Guide for the subtree command reference pages.
Compaq provides the RPC Event Logger, which records information about
operations relating to the execution of an application interface. See
the chapter titled Application Debugging with the RPC Event Logger for
details.
Compaq provides the name service interface daemon (nsid), also known as
the PC Nameserver Proxy Agent, to allow RPC communication with personal
computers running the DCE-compatible Microsoft RPC. The nsid enables an
RPC application on DOS, DOS Windows, and Windows NT to perform
name-service operations that are available through RPC, as if the RPC
applications on the PC are directly involved in the full CDS namespace.
For more information on using PCs with DCE, refer to Distributing
Applications Across DCE and Windows NT.
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